Lifting-jack



(No Model.) I 2 Sheets-Sheet 1.

A. A. STROM-I LIFTING JACK.

No. 359,411. Patented Mar. 15, 1887'.V

fnl

2 Sheets-Sheet 2 (Ndmoael.)

A. A. STROM. LIPTING JACK.

Patented Mar. 15, 1887.

@my *n NA PETERS. Pham-Lilli v l i Partnr FFICE@ AXEL A. STROM, OF AUSTIN, ILLINOIS. A

SPECIFICATION forming part of ALetters Patent No. 359,411, dated March 15, 1887-. Application filed I'Deccmber 2S, 1886. Serial No. 222,817. (No model.)

.To all wiz/0m it may concern.-

Be it known that I, AXEL A. STRoM, a citizen of the United States, residing at Austin, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Lifting-Jacks; and I hereby declare the following to be a full, clear, and exact description of the same.v

My invention relates, especially, to an improvement in the friction-clutch portion of a lifting-jack, it being my object to provide a device of very simple construction whereby liftingjacks in which my friction-clutch is used shall combine simplicity of construction, involving comparatively few partsV andl consequent inexpensiveness in the manufacture, with a high degree of effectiveness, resulting particularly from a lack of liability of its becoming impaired from any ordinary cause and from the principle of operation of the friction-clutch portion, which is positive in its action and precludes the possibility of the slipping of a load which it is employed to raise.

My invention consists, primarily, in the construction of the friction clutch, comprising two collars, one adjacent to the other, ona bar to be clutched which passes through them,and means whereby strain exerted against one collar from the other causes the collars to co-operate to clutch the bar.

My invention also consists in the general construction as well as in details of thc construction and combinations of parts of the clutch; an'd it further consists in the general as well as the particular constructionv of the lifting-jack involving my improved clutch device as the medium through which its function is performed.

In the drawings, Figure 1 is a perspective view of a lifting-jack embodying my improvements; Figs. 2 and 3, similar views of two clutch-collars; Fig. 4, a broken sectional side elevation of the lifting-jack of my improved construction; Fig. 5, a similar front elevation of the same; Fig. 6, a section taken on the line 6 of Fig. et and viewed in the direction of the arrow; Fig. 7, a section taken on the line 7 7 of Fig. Il and viewed in the direction of the arrows, and Fig. 8 a section taken on the line 8 8 of Fig. l and viewed in the direction of the arrows.

A is the bar employed in lifting-jacks as the lifting-bar, and provided for the purpose at its lower end with the foot portion o', which supports the weight to be lifted, and, in the case of a cylindrical bar, A,with a square heel portion, 1", (see Fig. 8, serving a purpose hereinafter stated. The lifting-bar is supported to work in a suitable standard portion, B, of the jack, which carries all of the operative parts and has suitable guides, q and p, for the bar A, handles y, and an enlarged portion, C, forming a receptacle or inclosure for the friction-clutch mechanism, and bearings for fulcruming the actuating-lever mechanism, all hereinafter more fully described.

The clutch mechanism is provided in sub` stantial duplicate, one being the lifting-clutch D, which is preferably, though not necessarily, the upper one, as shown, and the other theretaining-clutch E. The lifting-clutch comprises a collar, o, provided with trunnions m, and preferably beveled on one side, as shown at x, and a collar, a, having an extension or 1ug,m, on one edge and a downward and outward projecting lip, Z, on its opposite edge, beveled on its under side to correspond with the bevel w on the collar o, both collars o and n being imposed, respectively, the one upon the other on the bar A, to bring the beveled surface of the lip Z coincident with the bevel m onthe collar o, supported in opposite ends in the standard at the part G thereof, as shown, and affording a stop, and the extension or lug m over a bar, k', supported like the bar L, also to afford a stop in the part C of the standard, but near the rear side of the same, and sufiiciently high above the stop k to make the distance between the lug m and stop c/ the same as that between the lip Zand stop L. A bifur- 'cated lever, F, embraces the standard, upon which it is fulcrumed, to bring the arms respectively in line with the trunnions m on the collar o, and pivotal links i connect the arms of the bifurcated portion of the actuating-lever F With the collar o at its trunnions.

With the foregoing description the operationof the lifting-clutch D will be understood to be as follows: Downward pressure upon the actuating-lever forces the collar o against the collar n, and by its contact with and pressure against thelip Z on the latter forces the same IOO in a lateral direction, thereby pressing the portion of its opening adjacent to the part of the bar A at the side of the latter opposite the edge of the collar oz, provided with the lip, against the bar, which is thus clutched by the consequent friction produced. At the same time that the collar o forces the collar a in one direction, it is forced by the latter in the opposite direction, thus increasing the clutching force of the device D, and, obviously, the heavier the load imposed upon the bar to be lifted the greater the clutching force. \Vhcn the bar A is of cylindrical form, to prevent turning of the same in its bearings, I provide the square heel r', which serves also to guide the bar in the standard, without producing great friction. lt is not, however, necessary that the bar shall be cylindrical; but it may, obviously, have fiat sides, the openings through the collars of course conforming to the shape of the bar; nor need the collars be of the circular shape shown. Vhile the actuating-lever F cannot be pressed downward atits handle without producing the clutching effect ofthe collars o n upon the bar to raise the latter, raising of the lever-handle permits the collars to slide downward freely upon the bar, provided the latter is held stationary during the operation. 'lheretaining-elutch E aecomplishes this purpose, and comprises a lower collar, o, the exact counterpart of the collar o, except that it is unprovided with trunnions and seated on the bar-guide p in the standard, and surrounding the bar A, and a collar, n', upon the bar above the collar o', formed like the collar n and provided with trunnions mt, upon which to connect the arms of a bifurcated lever, F, which extends through an opening in the standard, as shown. The natural effect of the contiguity of the beveled under surface of the lip Z on the collar a', differing only from that on the collar n in the extra length of the last-named lip to permit the latter to strike against the stop Zt', for a purpose hereinafter described,with the beveled surface a" on the collar o', is to tend to force the two collars laterally in opposite directions, raising of the bar counteracting this tendency, while the weight, when raised and not sustained by downward pressure upon the lever F, tends to increase the opposite lateral pressure of the collars o and a', thereby holding the weight in whatever position it is raised, and while so held the clutch D may be lowered for a fresh grip still further to raise the bar by raising the handle of the lever F, the latter being worked up and down continuously,as in other lifting-jacks. To release the bar A from its raised position, and thereby lower a load imposed upon it, the handle of the lever F is depressed to remove the collar n out of contact with the collar o while the bar A is being raised and the weight held at the actuating lever F, when the handle of the last-named lever is permitted to rise, and thereby slightly lower the bar A and its imposed weight, if there be any, until the end ofthe lip Z on the collar n and the lug m thereon strike against the stops k and k', which produces separation of the collars of the lifting-clutch, overcoming their clutching effect and permitting the bar to fall.

XVhat l claim as new, and desire to secure by Letters Patent, is'

l. rEhe combination, with a bar, of a clutch for the same formed of two collars, one adjacent to the other,on the bar, which passes through them, and means, substantially as de scribed, whereby strain exerted against one collar from the other causes the collars to cooperate to clutch the bar, substantially as set forth.

2. The combination, with a bar, A, to be clutched, of a collar, o, a collar, a, having a beveled lip, Z, both collars being on the bar, which passes through them and the lip Z, engaging normally with the edge of the collar o, and an actuating-bar,F,substantially as and for the purpose set forth.

3. The combination, with a bar, A, to be clutched, of a collar, o, having a bevel, a', a collar, n, having a beveled lip, Z, both collars being on the bar, which passes through them and the lip Z, engaging normally with the bevel .r on the collar 0, and an actuating-lever, F, substantially as and for the purpose set forth.

4. In a lifting-jack, the combination, with the standard, of a lifting-bar, A, a lifting friction-clutch, D, on the bar, comprising a collar, o, and a collar, a, having a beveled lip, Z, to engage with the edge of the collar o, and an actuating-lever, F, connected with the collar o, substantially as and for the purpose set forth.

5. In a lifting-jack, the combination, with the standard, of a lifting-bar, A, a lifting frictionclutch, D, on the bar, comprising a collar, o, and a collar, o1, having a beveled lip, Z, to engage with the edge of the collar o, an actuating-lever, F, connected with the collar 0, and a. retaining friction-clutch for the bar, substantially as and for the purpose set forth.

G. In a lifting-jack, the combination, with the standard, of a lifting-bar, A, a lifting friction-clutch, D, on the bar, comprising a co1- lar, o, and a collar, n, having a beveled lip, Z, to engage with the edge of the collar o, an actuating-lever, F, connected with the collar o, stop mechanism, substantially as described, to release the clutch D at will, a retaining friction-clutch for the bar, and means, substantially as described, for releasing the retaining friction-clutch at will, substantially as and for the purpose set forth.

7. In a lifting-jack, the combination, with the standard, of a lifting-bar, A, a lifting frietion-clutch, D, on the bar, comprising a collar, o, and a collar, n, having a beveled lip, Z, to engage with the edge of the collar o, an actuating-lever, F, connected with the collar o, stop mechanism, substantially as described, to release the clutch D at will, a retaining frictionclutch, E, on the bar, comprising a collar, o',

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IIO

and a collar, oz', having a. beveled lip, Z, to

engage with bhe edge of the collar o', and

means, substantially as' described, for Vreleesin g the clutch E at Will, substantially as and for 5 the purpose seb forth.

8. A lifting-jack comprising, in combination, a standard, a lifting-bar, A, aliftaing friction-clutch, D, on the bar, comprising a col- 1er, o, having a bevel, w, and e collar, n, hav- 10 ing a beveled lip, Z, to engage with the collar o at the bevel x, and provided with e. lug, m',

stops 7c and 7c', an actuating-lever, F, connected with the collar o, a retaining friction-clutch, E, on the bar, comprising a collar, o', having a bevel, x, and a collar, n", having a beveled 15 lip, Z, to engage with the coller o at the bevel m thereon, and alever, F', connected with the collar n', substantially as described.

AXEL A. STROM. In presence of J. W. DYRENFORTH, FRANK L. DOUGLAS. 

